Dual purpose shipping and display cases having removable sections or panels fully or partially defined by perforated tear lines are known. such cases are typically formed from a one-piece blank which has been suitably cut and scored to enable subsequent folding of the blank into a closed case. The removable section(s) is generally defined at least in part by a plurality of perforated lines and may be separated from the closed case by loosening the section from the other part of the case and then tearing along the perforated lines.
The display function of the case is necessary for use in related outlets such as supermarkets, discount stores and the like to enable display of selected products without it being necessary to shelve them.
The inclusion of perforation lines to enable display by easy removal of portions of the case reduces the structural integrity of the case. Unwanted opening of these lines exposes and subjects the articles contained therein to loss or theft, resulting in delayed or untilled orders, spillage, and ultimately increased expense to consumers.
Generally, shipping/display cases are stacked one upon the other to conserve space. This imposes certain stresses on the cases. The cases thus require a certain compressive strength to resist crushing stress from excessive weight. The lower layers must support the weight of the cases above them and this imposes a strain, especially on the vertical portions of the lower container. U.S. Pat. No. 2,922,560, for example, deals with strengthening various vertical portions of a case.
Stressful treatment of the cases is to some extent uncontrollable, e.g., tall heavy stacks of the filled cases are commonly needed or used for maximum efficient utilization of warehouse or cargo space, which develops high stress on the lower layers of the stacks. Also, inadvertent opening is especially likely during storage or shipment of relatively heavy articles.
The problem of inadvertent opening of perforation lines as well as crushing of the cases is compounded by the desire to employ as little case material, i.e., case weight, as possible, in the interest of materials cost savings. A reduction of the case weight is accompanied by a diminution in case strength and capability of containing articles without tearing, especially for articles of substantial weight. Thus, while cases of lesser weight, i.e., less material, thinner panels and flaps, etc., are desirable from an economic point of view, as well as for ease of removing the removable sections, structurally strong and stable cases which reliably contain the contents therein during shipping and handling are equally desirable. These objectives are at cross purposes and no combination shipping and display case is known which optimally balances these competing objectives.
The ratio of the weight of the contents of the case to the weight of the case itself may be viewed as a measure of packaging efficiency. Thus, higher ratios correspond to more efficient packaging. However, there are practical limits beyond which the case strength is so low relative to the load that a reliable package is not feasible. Furthermore, this ratio is generally less for cases having removable sections due to the inclusion of perforation lines, compared to the generally stronger cases that can be fabricated without removable sections.
The difficulty of known dual purpose cases in reliably containing bottles or containers in a case of minimum weight, is compounded by the desire for large removable sections. Large removable sections are desired to permit a substantial and attractive display of the articles and to facilitate removal of unit amounts thereof from retail shelves or counters by purchasers. However, large removable sections weaken correspondingly large portions of the relatively light weight case.
T. J. Lipton Company has employed a commercial shipping and display case for products such as salad dressings which employs full side and rear panels to assist in providing compressive strength to cases to resist crushing caused by stacking or other forces which act on the top of the lower tiers of cases. Other combination shipping, display cases have been used, for example, U.S. Pat. No. 4,946,042, provides an easily openable cut out portion of a shipping case to facilitate display of the contents. U.S. Pat. No. 4,574,945 deals with a shipping display case which has an integral liner to help protect the contents from cuts when the shipping case is converted to its display function.
Cases with additional liners and strengthening panels employ more corrugated board than shipping display cases without these additional strengthening and protective layers. In view of the ever increasing load of solid waste, it is, of course, desirable to avoid any excess use of paperboard or corrugated board. While still maintaining the compressive strength necessary to substantially avoid crushing of the lower tiers of cases in stacks and enabling easy conversion from shipping to display mode without employing protective panels and shields.